1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a connecting part of an outer circuit in a liquid crystal display (LCD) panel and a fabricating method thereof.
2. Discussion of the Related Art
FIG. 1 shows a schematic structure of a conventional liquid crystal display panel.
A pixel array is in the middle of the substrate. A gate driver and a data driver, which are collectively called a driver, are at the left side and upper side of the pixel array, respectively. The gate driver drives each pixel of the pixel array and the data driver applies a data signal to each pixel. The gate and data drivers are connected electrically to each of the pixels. A driving circuit which is connected to the outer circuit 10 supplying a data input signal splits the data signals to be carried in turn to each pixel in the pixel array according to its own control signal.
In a liquid crystal display (LCD) device having a driving circuit and a substrate in one body, an outer circuit and the driving circuit are connected to each other by a pad when there are plenty of data input lines and control signal lines which are supplied from the outer circuit of the panel. Hence forward, the pad which connects the outer circuit to the driving circuit and the peripheral part are called a connecting part of the outer circuit. For the methods of connecting the panel to a driving IC to form the driving circuit with the substrate, Wire Bonding (WB), Tape Automated Bonding (TAB), or Chip on Glass (COG).
FIG. 2 shows a portion of the connecting part of the outer circuit and the driver shown in FIG. 1, and FIG. 3 shows a schematic layout of the conductive lines for connection and the pads of the connecting part of the outer circuit in FIG. 2.
A plurality of pads 21 are formed in a connecting part of the outer circuit 20. Each pad 21 is connected to each chip of the driving circuit which is a data outer circuit source (not shown in the drawing) and receives a data driving signal. Each data driving signal diverges at the driver and then carries the data signal to the pixel array. FIG. 2 shows that a single wire 22 diverges into four wires by the driver. As a plurality of pads 21 are densely located at the connecting part of the outer circuit 20, space is needed for arranging these wires 22 to be connected to the driving (switch) circuit in which the wires 22 are to be connected to the pads 21. Namely, the wires 22 connected to a plurality of pads 21 , which are densely arranged, should have a certain space to prevent an electrical short in the arranged space.
Wires 22 are connected to a connecting part of the outer circuit and arranged to one direction in a conventional art. Accordingly, each wire is formed to have a long line to secure a space which prevents electrical short. As a result, in the conventional art, a small and light panel is unable to be fabricated due to the large amount of space occupied by the wires.
Accordingly, the present invention is directed to a connecting part of outer circuit in liquid crystal display panel and a fabricating method thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a connecting part of an outer circuit and fabricating method thereof which improves the arrangement of the wires connecting directly the connecting part of the outer circuit to the driving circuit to minimize the space required for the wires.
Additional features and advantages of the invention will be set forth in the description which follows and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a connecting part of an outer circuit in a liquid crystal display panel of the present invention includes a plurality of pads formed on a substrate and connected to the outer circuit, at least a first connecting wire connected to each of the pads one on one and arranged in a first direction, and at least a second connecting wire connected to each of the pads except the pads connected to the first connecting wires and arranged in a second direction.
In another aspect of the present invention, a connecting part of an outer circuit in a liquid crystal display panel includes a substrate, a first connecting wire on the substrate, a first insulating layer covering the first connecting wire, a first contact hole through the first insulating layer wherein the first contact hole exposes a portion of the first connecting wire, and a pad connected to the first connecting wire through the first contact hole. The present invention further includes a second insulating layer covering the first connecting wire, a second contact hole in the second insulating layer wherein the second contact hole exposes a portion of the pad, and a transparent conductive layer connected to the second connecting wire through the second contact hole.
In a further aspect of the present invention, a method of fabricating a connecting part of an outer circuit in a liquid crystal display panel includes the steps of forming a first connecting wire on a substrate, forming a first insulating layer covering the first connecting wire, forming a first contact hole in the first insulating layer wherein the contact hole exposes a portion of the first connecting wire, and forming a pad connected to the first connecting wire through the first contact hole.
In another aspect of the present invention, a connecting part of an outer circuit in a liquid crystal display panel includes a substrate, a pad connected on the substrate, the pad being connected to the outer circuit, a first insulating layer on said pad, a first connecting wire on the first insulating layer, a second insulating layer covering said first connecting wire, a first and a second contact holes in the first and second insulating layers, the first and the second contact holes exposing portions of said pad, a third contact hole in the second insulating layers, the third contact hole exposing a portion of said first connecting wire; and a transparent conductive layer connected to the exposed portions of said pads and the exposed portion of said first connecting wire through said first, second and third contact holes.
In a further aspect of the present invention, a method of fabricating a connecting part of an outer circuit in a liquid crystal display panel includes the steps of forming a pad on a substrate, the pad being connected the outer circuit, forming a first insulating layer covering the pad, forming a first connecting wire on the first insulating layer, forming a second insulating layer covering said first connecting wire, forming a first and a second contact holes exposing portions of said pad in the first and second insulating layers and a third contact hole in the second insulating layer exposing a portion of said first connecting wire; and forming a transparent conductive layer connected to the exposed portions of said pads and the exposed portion of said first connecting wire through said first, second and third contact holes.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide farther explanation of the invention as claimed.